Well, one interesting plot could be Clary slowly regaining her memories through a series of magical encounters. Maybe she finds an old object that triggers flashes of her past. Another could be that her friends play a crucial role in helping her get her memories back, like they take her to special places related to her past. And a third possibility is that there's some sort of enemy who is trying to stop her from getting her memories back, which adds a lot of suspense to the story.
In the comics, Vision regains his memories through a series of events and interactions that trigger his internal processes and reconnect him to his past.
Clary is the central figure. Valentine might also be involved in some fanfictions, either as an obstacle trying to prevent Clary from getting her memories back because he doesn't want her to discover certain secrets, or in a more complex way where his past actions are somehow related to the loss of her memories in the first place. And of course, the Lightwood family members are likely to be involved, given their importance in Clary's life and the Shadowhunter community.
Hermione could be the one. With her vast knowledge of the wizarding laws and her sharp intellect, she might dig up some old regulations that prove Harry's right to his money. She would then fight tooth and nail in the wizarding courts or against the goblins at Gringotts to get his money back.
Maybe he discovers some legal loophole in the wizarding world's financial system that allows him to reclaim his inheritance. For example, if there was some improper handling of his family's vault by the goblins at Gringotts, he could use that as a basis to demand his money back.
Well, if we look at the 'Naruto gets his parents back fanfiction', Naruto's character development might take a different turn. Instead of relying solely on his friends and mentors like Iruka and Kakashi, he'd have his parents' direct guidance. His father, Minato, could train him in advanced ninjutsu. His mother, Kushina, could give him all the motherly love and care he was deprived of. This would likely make Naruto more confident and perhaps a bit more relaxed as he wouldn't have that deep - seated longing for family anymore.
Perhaps in the fanfiction, there's a magical object or a powerful spell that can restore his wings. But to find this object or cast the spell, Lucifer has to face many challenges. He might have to team up with some unexpected allies, like a group of angels who initially didn't trust him but later see his determination to get his wings back and decide to help.
The 'harry gets his mail back fanfiction' could start with Harry noticing that he hasn't received any mail for a while, which is strange in the wizarding world. He starts to suspect foul play. As he investigates, he finds out that there is a new spell that has been cast on the mail delivery system that is misdirecting his mail. With the help of Ron's family's connections in the wizarding world (since they are so well - known in the wizarding community), Harry is able to track down the source of the spell and reverse it, finally getting his mail back.
In a 'kaneki goes back in time fanfiction', perhaps Kaneki goes back to when he was still a normal college student. He then decides to study more about ghouls secretly. He could use this knowledge to try and find a way to co - exist peacefully between ghouls and humans from the very start. He might start by trying to change the views of some key people in the CCG, using his understanding of their future actions.
Yes, there are likely such fanfictions. Many fanfiction writers like to explore the idea of Itachi coming back to life with his memories intact. This allows for interesting character interactions, especially with Naruto. Itachi could use his wisdom and skills once again, and his relationship with Naruto could further develop in new and unexpected ways.